You should complain locally first – to the Latvian authorities and courts. International and European institutions will not accept your claim if you have not first tried to complain to the local institutions. You can only go to international and European institutions if you think that the violation of your rights have not been remedied by Latvian institutions.
Complaints to prison administration
Prison staff and the head of your prison are responsible for the maintenance of good conditions and order at the prison. They are supervised by an institution called the Latvian Prison Department. Therefore, you can generally submit all complaints about the prison staff or fellow inmates to either the head of the prison or to the Latvian Prison Administration.